Disclosed is a composition containing sulfonated keratin with molecular weight distribution of about 96.8% 100 kDa to 100 Da and about 3.2% 250 kDa to 100 kDa, at least one cationic surfactant, and optionally an aqueous carrier. Generally the sulfonated keratin is produced by a method involving treating wool with about 0.5 to about 1N NaOH in a bath volume:wool weight of about 5:1 to about 10:1 at about 40° C. to about 65° C. for about 4 to about 8 hours with dosing about every 1 to 3 hours with about 1% to about 10% by weight of bath of hydrogen peroxide. Also disclosed is a method for treating a keratin based substrate (e.g., hair) involving contacting or applying the substrate with the composition.
The surface of human hair is damaged by combing, washing, and brushing, culminating in “split ends” where the inner cortical layer is exposed. The damage to human hair through environmental exposure, mechanical stress and abrasion, and chemical processing can be alleviated in part by conditioning treatments to correct for the problems of split ends, roughness, and dullness. Conditioners are used to improve wet and dry compatibility as a separate treatment for imparting softness and suppleness and preventing dryness and static fly-away in hair combing. After conditioning, hair is left with an aesthetically improved appearance but with little or no restoration of strength. Loss of 58% hair protein of 48 kDa and 60 kDa was reported after permanent waving (Han, Mi-Ok, et al., J. Cosmet. Sci., 59 (3): 203-215 (2008). Aminofunctional silicone emulsions were particularly effective in conditioning damaged hair to provide effective protection from damage associated with bleaching and oxidative dyeing (Berthiaume, M. D., et al., J. Soc. Of Cosmetic Chemists, 46(5), September/October 1995). High-viscosity, high amine content silicone microemulsions (e.g., dimethicones, cyclomethicones, amodimethicones, and trimethylamodimethicones) have been found to provide significant conditioning properties to damaged hair, restore shine and smoothness, and ease of combing in correcting for fly-away hair and wet and dry combing performance. However, silicone additives are known to build up and cause dullness and a greasy-appearance.
We have found that sulfonated keratin with molecular weight distribution of about 96.8% 100 kDa to 100 Da and about 3.2% 250 kDa to 100 kDa can replace silicone in formulated conditioners to provide the desired beneficial effects.